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प्रश्न
How many words can be formed from the letters of the word 'SERIES' which start with S and end with S?
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उत्तर
The word SERIES consists of 6 letters including two Ss and two Es.
The first and the last letters are fixed as S.
Now, the remaining four letters can be arranged in\[\frac{4!}{2!}\]ways = 12
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